Fish lure



July 21, 1942. oss 2,290,422

ELECTRIC SIGNALING SYSTEM Filed Feb. 1, 1941 Fig. 5.

LESLIE FOSSETT AI'TORIVEY Patented July 21, 1942 ELECTRIC SIGNALINGSYSTEM Leslie Fossett, Bexleyheath, England, assignor to SiemensBrothers & Co. Limited, London, England, a British company ApplicationFebruary 1, 1941, Serial No. 376,970 In Great Britain February 5, 1940 3Claims. (Cl. 11940) This invention relates to electric signaling systemsand more particularly to systems in which a signal or indication isgiven consequent on the operation oi apparatus by alternating current.

It has a special field of usefulness in telephone systems.

In an alternating current electric signaling system in which kicks oiunidirectional current may occur in the signaling wires, for instance bythe charge or discharge of a condenser, the apparatus, the operation ofwhich is to give a signal or indication, may be operated by such a kickand a false signal or indication given.

The present invention has in view improved means of a. simple naturewhereby such false si nals are prevented without the provision of delaymeans exterior to the signal receiving apparatus or reduction insensitivity of the apparatus.

According to the present invention the signal receiving apparatus andits connection to the signaling circuit are so arranged that one effectis produced by one half cycle of alternating current and another eifectis produced by a succeeding half cycle in the opposite direction and asignal is given only if the first effect has persisted until the secondeii'ect has been produced and both ellfects are present simultaneously.The effects are the productlon'of'ma'gnetic fluxes in a magnetic circuitand these fluxes may be produced in dlflerent relays or in one relay. Inthe former case the production of a magnetic flux by one halfcycle ofcurrent may bring the operation of one of the relays and the productionof a flux by the following half cycle of current may bring about theoperation of another of the relays and in the latter case the operationof the relay may result from the existence of opposing fluxes consequenton the persistence of the flux clue to one half cycle after a flux due 4to the succeeding hali cycle has been produced. Registering or lockingarrangements may be Provided to register the occurrence of these effectsand only when the existence of simultaneous effects has been soregistered is a persistent circuit closed to give a signal.

In carrying out the invention two windings of a relay or the windings oftwo relays are connected to the signaling'wlres, a rectifier beingassociated with each winding, the two rectifiers being so connected thatone winding is energised by current of one half cycle of alternatingcurrent and the other winding is energised by current of the succeedinghalf cycle. In the case of separate relays the release of the first to'be operated is delayed while the flux in the other relay is growingthus both relays will be operated for a short time and during this timea registering or looking circuit may be closed. The delay may be broughtabout by connecting the rectifiers as shunts to the line windings of therelays. In the case of a single relay this may be of 'the shunt fieldtype, with two line windings shunted respectively by oppositelyconnected rectifiers. The relays or relay may have locking windingsconnected over contacts of the two relays in series, there being onewinding on each limb of the shunt field relay, or series connectedcontacts oi each relay may close a circuit for a registering relay. Thesignal circuit may'be closed by a contact of one of the line relays orserially connected contacts of both relays. In the first case ii thisrelay should be operated by a unidirectional kick the operation will beof a transitory nature and a signal may be given although it may not bepersistent.

In the application of the invention to a telephone system to give asignal in response to the reception of ringing current, the relays orwindings of the single relay and the associated rectificrs may beconnected to the signaling wires over a. condenser and the connectionma-y'inclucle contacts of a cut-off relay included in the sleeve circuitof a Jack or break contacts of a jack. The locking circuit may alsoinclude similar contacts or the contacts of an answering key if therelays are connected in a cord circuit. The two line windings each withits rectifier may be connested in series across the signaling wires. Ifthe windings and the rectifiers are in series a parallel connection ofthe combination across the signaling wires may be employed. A contact ofeach of the relays is included in the circuit of the signaling lamp butif there is no objection to a transitory signal, e. g. a flicker of thelamp, the lamp circuit may include a contact of only one of the relays.

Reierence will now be had to the accompanying drawing in which dliferentembodiments are illustrated diagrammatically. Figs. 1, 2 and 3 showarrangements in which two relays with looking windings forming aregistering circuit are employed, Fig. 1 showing the relays connected inthe 'cord circuit of a switchboard, Fig. 2 show ing the relays connectedto a branching jack and Fig. 3 showing the relays connected to a breakjack all of which connections may be as-- sumed to be in the circuit ofa telephone switchboard. Fig. 4 shows an arrangement employing tworelays with a separate registering circuit and Fig. an arrangementshowing the use of a shunt field relay.

Reference will first be had to Fig. l. The signal receiving apparatusincludes the relays LA and LB and the rectlfiers RA and RE. Theoperating windings oi the relays are the lefthand windings and these areconnected in series with one another and a condenser K across the tipsand rings of two plugs PA and PC. The left-hand winding 0! relay LA isshunted by rectifier RA and the leithand winding of relay LB is shuntedby rectifier RB. The right-hand windings are connected in series withone another and with serially connected contacts of each rclay and breakcontacts k oi a key which in a telephone system may be the answeringkey. A contact 2 of one of the relays, or if desired, se riallyconnected contacts of both relays are connected in the circuit of asupervisory lamp L.

If a unidirectional kick occurs on the line wires, due for instance to acondenser charge or discharge and the polarity is such that relay LA isoperated, relay LB will in eilect be short-circuited by rectifier RB.Similarly ii the polarity of the kick is such that relay LB is operatedrelay LA will be short-clrculted by rectifier RA. In either event onlyone relay will be operated and the locking circuit over the right-handwindings of the relays will not be completed. Contact 2 of the relayoperated may close the circuit of the supervisory lamp L momentarily butno great disadvantage need arise from this. In any case a flash on lampL can be avoided by including serially connected contacts of both relaysin the lamp circuit. If alternating current is impressed on the line thefirst half cycle will operate one of the relays, for example relay LA,and the following hall cycle will operate the other relay, in theexample relay LB. The effect of rectifier EA will be to delay somewhatthe release of relay LA and in any case by suitable design this delaymay be caused to extend over a period until relay LB has been operated.As both relays are in an operated condition at the same time the lockingcircuit over their right-hand windings will be closed over contacts lotand lbi and key contacts k. The existence of the eifects represented bythe operation of both the relays is thus reg istered and lamp L willcontinue to glow steadily. The relays may be released and the lampextinguished by the momentary depression of the key thereby openingcontacts k.

The arrangement shown in Fig. 2 is similar to that shown in Fig. 1. Thesignal receiving apparatus is here connected over contacts col and 002of a cut-cit relay to a pair of line wires terminating on the springs ofa jack J. The locking windings include a contact 003 of the cut-offrelay in place of the key contacts I: in Fig. The cut-oil relay CO isconnected to the slee e of the lack in the well-known manner. Theoperation of the apparatus is exactly as described in connection withFig. 1, the circuit of lamp L being closed when both relays are in anoperated condition at the same time. When a plug is inserted into thejack, relay CO is operated and the signal receiving apparatus isdisconnected from the line at contacts co! and 002 and contact (:03opens the locking circuit thereby bringing about the extinguishing oflamp L. This arrangement may be used for receiving a calling signal, thelamp L beings. calling lamp.

In Fig, 3 the signal receiving apparatus is shown connected over springsof a break jack J to a line terminating on the line springs of the Jack.In this arrangement jack springs take the place of the contacts of thecut-off relay of Fig. 2. The operation of the signal receiving apparatusis as described in connection with Fig. 1.

In the arrangement shown in Fig. 4 the relays LA and LB have only asingle winding each. A further relay C is provided the operating circuitof which includes serially connected contacts lal and lbi of relays LAand LB. Relay C also has a locking circuit including contact cl andanother contact '6, for example'lireak contacts cl 2. key, for thepurpose of unlocking the relay. The circuit of lamp L may be closed by acontact of any of the relays, pieferably by a contact c2 of relay C sothat flashing of the lamp due to unidirectional kicks is avoided. Inthis arrangement relays LA and LB are operated when alternating currentis received, the first relay to be operated not releasing before thesecond has operated. When both relays are in an operated conditionsimultaneously the operating circuit of relay C is closed over contactsla! and lbi and relay C locks up over contact cl and contact 10 and atcontact 02 closes the circuit of lamp L. Relay C is released and thelamp extinguished by opening contact is by suitable means.

In Fig. 5 an arrangement employing a shunt field relay LC is employed.This relay has two line windings (I) and (II) associated with themagnetic circuit in the well-known manner. It has also two lockingwindings (III) and (IV). The line windings are shunted by rectifiers RAand RB in a similar manner to relays LA and LB oi the preceding figures.Current through one of the line windings is ineffective in operating therelay as there would be no exterior flux. If one line winding is soenergised, the flux due to it does not die away before the other linewinding is energised and the fluxes due to both windings being energisedoppose one another and the armature is attracted. Attraction of thearmature closes contact lci and the locking windings (Ill) and (IV) ofthe relay are energised in the same sense as the line windings (I) and(II) and the relay remains in an operated condition. Contact 102 closesthe circuit of lamp L. The relay is released by the opening of contact10 in some suitable manner.

By a. suitable arrangement of the resistance or the windings of therelays in the registering circuit the lamp L may be included in thatcircult in any of the arrangements described and illustrated.

I claim:

1. In combination, a line upon which currents of opposite polarity areimpressed at different times. a relay connected to said line andoperated only by current of a particular polarity when such current isimpressed upon said line, a normally ineifective locking circuit forsaid relay, and means controlled by current of the opposite polarity, ifsame is impressed upon said line within a predetermined interval aftercurrent of said particular polarity has ceased to be impressedthereupon, for rendering said locking circuit effective to maintain saidrelay operated.

2. In combination. a line over which current flows in differentdirections at different times, two relays connected to said line. one ofsaid relays operated only by current flowing over said line in onedirection and the other of said relays operated only by current flowingover said line in the opposite direction, and a locking circuitcontrolled by said relays for maintaining said relays operated wheneverthey have been operated substantially concurrently by current flowingover said line.

3. In combination, two relays, means connecting the windings of saidrelays in series in a circult, a rectifier bridging the winding of oneoi said relays to render that relay non-responsive to current flowingover said circuit in a particular direction, a rectifier bridging thewinding of the other of said relays to lender that relay nonresponsiveto current flowing over said circuit in the opposite direction, anormally open contact on each of said relays, and a locking circuitcontaining said two contacts in series for maintaining said relaysoperated independently of said first circuit if said relays are operatedconcurrently over said first circuit.

LESLIE FOSSETT.

